Galactic Center VR: bringing Sgr A* and friends to your living room

“Galactic Center VR” is our public outreach app available on two VR platforms: Steam and Viveport. Using the HTC Vive VR headset (and available in beta for equivalent headsets), which has motion tracking and six degrees of freedom (6dof), the user is transported to the inner parsec around Sgr A*, our galaxy’s supermassive black hole. They can move anywhere and look anywhere they choose as the Galactic center undergoes 500 yr of time evolution from orbiting Wolf-Rayet stars and their winds, which gives the user the complete freedom to explore material flowing towards the supermassive black hole as they see fit. Developed with the game engine Unity and the SteamVR package, the app displays a position- and size-dependent marker for each element in the hydrodynamic simulation that is colored according to the element’s density and X-ray emissivity. Then the summation of these markers along the user’s viewing vector at that particular time yields a composite of column density (dominated by the cold gas) and X-ray emission (only from hot gas). The black hole and orbiting stars have their own markers, so all elements in the hydrodynamic simulation are shown in the VR app, and the animation controls allow the user to pause the simulation, play it at various speeds forward in time, and play the simulation backwards.

After presenting the no-time-evolution version via one-on-one demos to eclipse aficionados and locals in July 2019 for the solar eclipse in the north of Chile, as well as earning a metaphorical seal of approval from a Nobel Laureate, we packaged the app with the aim of being self-contained in order to widely distribute it to VR users. This involved adding a tutorial explaining the simulation; incorporating options to look at only the column density, only the X-rays, or both; adding the option to see just one wind’s elements at a time; including the necessary VR-controller-attached instructions and menus for the app’s successful navigation; and providing options to use the app completely in English or Spanish. After submitting the marketing material and having the VR stores themselves test the app, “Galactic Center VR” is now available for free on Steam and Viveport, two of the most popular VR gaming platforms.

This presentation will discuss the continued development of the app with Unity and SteamVR, the unique exploration ability afforded only via VR due to its ability to move and look anywhere, and some things learned via submitting the app for distribution. We will also focus on our latest additions to “Galactic Center VR”, which incorporate new simulations that produce a disk around Sgr A* and also include the effects of the OB stars.